<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
<script>

'use strict';
///for正序
var arr = ['Bart', 'Lisa', 'Adam'];
for(var a=0;a<arr.length;a++){
    console.log('Hello,'+arr[a]+'!!!');
}
///for逆序
for(var b = arr.length-1;b >= 0;b--){
    console.log('Hello,'+arr[b]+'!!!');
}
///while正序
var c = 0;
while(arr[c]){
    console.log('Hello,'+arr[c]+'!!!');
    c++}
    ///while逆序
    var d = 2;
    while(arr[d]){
console.log('Hello,'+arr[d]+'!!!');
    d--}
</script>

</head>
<body>
    
</body>
</html>